Texas A&M quarterback Johnny Manziel could become the first freshman ever to win the Heisman Trophy. Unfortunately, this does not mean he is on his way towards anything more in the future.

Manziel has had an incredible first year as a starting collegiate quarterback. He broke an SEC record for total yards with 4,600. He has thrown 24 touchdowns and added 19 more on the ground.

The Texas native has excelled as a runner—he is third among quarterbacks in rushing yards—and as a passer, where he has one of the top passer efficiency ratings in the country.

These incredible statistics, combined with his highlight reel plays, make him the favorite to take home college football's most prestigious award.

When that happens, however, the first thing people will want to know is if he can be the next Archie Griffin. To this point, the former Ohio State running back is the only person ever to win multiple Heismans.

While having as many as three more chances to win provides Manziel a good chance, there are many factors that can prevent this from happening.

Since 2003, five of the eight Heisman winners returned to school the following year, one of which had two more seasons in college. None of them were able to win the award again.

Sometimes, the problem is simply bad luck or an injury.

Sam Bradford had incredible stats in 2008, most impressively throwing 50 touchdown passes. The next year, a collarbone injury sidelined him for most of the season. He then declared for the draft and ruined any opportunity for a second Heisman.

Mark Ingram of Alabama also dealt with injury problems and was only able to gain a little more than half as many rushing yards the year after winning the award.

Other times, there are simply better players that steal the attention after the public loses interest in the a previous winner.

That happened in consecutive years in 2004 and 2005. Oklahoma's Jason White had similar stats to when he won year before, but Matt Leinart and USC took over the headlines and the top individual award.

The next season, Leinart finished third behind Reggie Bush and Vince Young despite improving his passer efficiency.

These circumstances would be bad, but the one that Manziel and his supporters should be more afraid of is simply decreased production.

Tim Tebow is likely the best statistical comparison for Manziel. Both are mobile passers that dominated the SEC and put together solid passing numbers.

In his sophomore season, Tebow rushed for 895 yards with 23 touchdowns. By his junior year, opponents were starting to figure out how to stop him and his numbers decreased to 673 yards and 12 touchdowns.

Of course, his Florida Gators won the national championship, but he was still unable to win that elusive second Heisman.

There was no book out on Manziel this season, which contributed to his success. Once teams get more film on the young player, he will be easier to defend.

An additional problem that he has to deal with is the amount of players that will not be around next season.

According to the team's official depth chart, three starting receivers and the starting tight end are all seniors. While he will be able to keep throwing to players like Mike Evans, the experience of Ryan Swope and Uzoma Nwachukwu helped significantly this season, especially in the end zone.

Those two players accounted for 13 of the quarterback's 24 touchdown passes this year.

In addition, center Patrick Lewis will graduate and left tackle Luke Joeckel is likely to enter the NFL Draft.

Without this support, it will be tough for the Aggies to continue winning at the current rate and for Manziel to repeat his level of production.

There will be other talented players, but nothing is ever guaranteed in life. It is unknown how the young quarterback will react to these changes.

Manziel has loads of talent and can still get better. However, it will be much tougher trying to return to his current level of play to take home a second Heisman trophy.